Art of extracting radium from radium-barium salts and the like



effecting economles Patented June 8, 1926.

warren srares PATENT OFFICE.

HERMAN FLECK, or

No Drawing.

GOLDEN,

to the extraction of radium values from radiumbarium'salts such as sulfates, chlorides,

bromides, et

cetera and is intended to cheapen and expedite the recovery terial.

Heretofore it has been of radium compoun of time, labor and mads by the practice to convert the relatively insoluble sulfates of radium and barium into soluble compounds such as chlorides and then follow a process of separating the radium from the barium by boiling these salts in water which operation is continued until the solution reaches the desired stage of crystallization when the solution is allowed to cool with the consequent formation of radium barium salts in crystalline form in which the radium occurs in a higher ratio than before such treatment.

traction or concentration crystallization is very slow,

expensive, and is not found in the salts This method of exby differential laborious and applicable to salts where the ratio of the radium to the barium content is extremely low.

The process herein described is based on the discovery made by to efiect such separation tent from the me that it is possible of the radium conbarium present by putting the radium barium salts into solution by means of a solvent reagent preferential solvent action upon content than it has upon pound present.

that has a greater or the radium the barium com- There are two great advantages gained by the application offthis process. First,

for recovery r differential solution it makes it possible to treat dium barium salts of such low ratio of radium content to the barium content that they are not commercially workable by secondly the vastly more economical material.

It is not of course all the reagents which a in practicing solution but oxalic acid forms a very for this purpose since I have it has a mar the crystallization process and differential solution process is in time, labor and possible to now name re available for use such a process of differential I have found in practice that satisfactory reagent discovered that ked diiferentlal solvent action upon the radium barium salts favorable to the extraction or concen tration of the raditrative and not prescriptive.

COLORADO, ASSIGNOR TO WILLIAM A. J. BELL, OF DENVER, COLORADO. ART OF EXTRAGTING RADIUM FROM RADIUM-BARIUM SALTS AND THE LIKE.

gust 15, 1922. Serial No. 582,089.

um content, which I have taken advantage of in the following manner. a

I may take a radium barium salt such as radium barium sulfate, radium barium chloride, bromide or the like and to every 5 parts of such salt add say for example 20 parts of oxalic acid and 20 parts of water, preferably distilled water free from sulfate, and boil and stir the mixture for 30 minutes more or less, the amounts stated being illus- The hot solution is then run off through a filter and the filtrate is diluted by the addition of say approximately 600 parts more of water.

The diluted filtrate is allowed to stand for a sufficient period to permit the radium con-- tent to preclpitate. Such precipitation is preferably hastened by the addition of a small quantity of sulfuric acid, with the con-. sequent deposit of the radium-barium content as a radium barium sulfate. The liquid is then drawn off through a filter and may be treated by evaporation and crystallization to recover the oxalic acid content for further use. 8

The precipitate will be found to contain a very much higher ratio of radium to barium than did the original salt from which it was obtained and is amenable to a repetition of the same process to efiect an even higher degree of concentration, the process being repeated as many times as may be necessary to secure the desired concentration. Instead of repeating the differential solution rocess it may be practical or advantageous to continue the further extraction of radium by the crystallization method after the radium barium salt has been brought to such a ratio of radium to .barium by the present process that it can be profitably extracted by the crystallization process.

Going back now to the original oxalic acid boiling tanks from which the liquor containing radium barium compounds in solution has been filtered off, as above described, we shall find a residue or tailing containing someradium barium content in i 

